From: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 170 ++++++++++++++++++++++++++++++++-
1 file changed, 165 insertions(+), 5 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 99ceb978c8b0..9c454c5b785c 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -960,6 +960,13 @@ memory.
__u8 pad2[30];
};
+If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the
+KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl.
+This requests KVM to generate the contents of the hypercall page
+automatically, and also to intercept hypercalls with KVM_EXIT_XEN.
+In this case, all of the blob size and address fields must be zero.
+
+No other flags are currently valid in the struct kvm_xen_hvm_config.
4.29 KVM_GET_CLOCK
------------------
@@ -4831,6 +4838,101 @@ into user space.
If a vCPU is in running state while this ioctl is invoked, the vCPU may
experience inconsistent filtering behavior on MSR accesses.
+4.127 KVM_XEN_HVM_SET_ATTR
+--------------------------
+
+:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_xen_hvm_attr
+:Returns: 0 on success, < 0 on error
+
+::
+
+ struct kvm_xen_hvm_attr {
+ __u16 type;
+ __u16 pad[3];
+ union {
+ __u8 long_mode;
+ __u8 vector;
+ struct {
+ __u64 gfn;
+ } shared_info;
+ __u64 pad[4];
+ } u;
+ };
+
+type values:
+
+KVM_XEN_ATTR_TYPE_LONG_MODE
+ Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This
+ determines the layout of the shared info pages exposed to the VM.
+
+KVM_XEN_ATTR_TYPE_SHARED_INFO
+ Sets the guest physical frame number at which the Xen "shared info"
+ page resides. Note that although Xen places vcpu_info for the first
+ 32 vCPUs in the shared_info page, KVM does not automatically do so
+ and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used
+ explicitly even when the vcpu_info for a given vCPU resides at the
+ "default" location in the shared_info page. This is because KVM is
+ not aware of the Xen CPU id which is used as the index into the
+ vcpu_info[] array, so cannot know the correct default location.
+
+KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
+ Sets the exception vector used to deliver Xen event channel upcalls.
+
+4.128 KVM_XEN_HVM_GET_ATTR
+--------------------------
+
+:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_xen_hvm_attr
+:Returns: 0 on success, < 0 on error
+
+Allows Xen VM attributes to be read. For the structure and types,
+see KVM_XEN_HVM_SET_ATTR above.
+
+4.129 KVM_XEN_VCPU_SET_ATTR
+---------------------------
+
+:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xen_vcpu_attr
+:Returns: 0 on success, < 0 on error
+
+::
+
+ struct kvm_xen_vcpu_attr {
+ __u16 type;
+ __u16 pad[3];
+ union {
+ __u64 gpa;
+ __u64 pad[4];
+ } u;
+ };
+
+type values:
+
+KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO
+ Sets the guest physical address of the vcpu_info for a given vCPU.
+
+KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO
+ Sets the guest physical address of an additional pvclock structure
+ for a given vCPU. This is typically used for guest vsyscall support.
+
+4.130 KVM_XEN_VCPU_GET_ATTR
+--------------------------
+
+:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xen_vcpu_attr
+:Returns: 0 on success, < 0 on error
+
+Allows Xen vCPU attributes to be read. For the structure and types,
+see KVM_XEN_VCPU_SET_ATTR above.
5. The kvm_run structure
========================
@@ -4996,13 +5098,18 @@ to the byte array.
.. note::
- For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR,
+ For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN,
KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
operations are complete (and guest state is consistent) only after userspace
has re-entered the kernel with KVM_RUN. The kernel side will first finish
- incomplete operations and then check for pending signals. Userspace
- can re-enter the guest with an unmasked signal pending to complete
- pending operations.
+ incomplete operations and then check for pending signals.
+
+ The pending state of the operation is not preserved in state which is
+ visible to userspace, thus userspace should ensure that the operation is
+ completed before performing a live migration. Userspace can re-enter the
+ guest with an unmasked signal pending or with the immediate_exit field set
+ to complete pending operations without allowing any further instructions
+ to be executed.
::
@@ -5327,6 +5434,34 @@ wants to write. Once finished processing the event, user space must continue
vCPU execution. If the MSR write was unsuccessful, user space also sets the
"error" field to "1".
+::
+
+
+ struct kvm_xen_exit {
+ #define KVM_EXIT_XEN_HCALL 1
+ __u32 type;
+ union {
+ struct {
+ __u32 longmode;
+ __u32 cpl;
+ __u64 input;
+ __u64 result;
+ __u64 params[6];
+ } hcall;
+ } u;
+ };
+ /* KVM_EXIT_XEN */
+ struct kvm_hyperv_exit xen;
+
+Indicates that the VCPU exits into userspace to process some tasks
+related to Xen emulation.
+
+Valid values for 'type' are:
+
+ - KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall.
+ Userspace is expected to place the hypercall result into the appropriate
+ field before invoking KVM_RUN again.
+
::
/* Fix the size of the union. */
@@ -6415,7 +6550,6 @@ guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf
(0x40000001). Otherwise, a guest may use the paravirtual features
regardless of what has actually been exposed through the CPUID leaf.
-
8.29 KVM_CAP_DIRTY_LOG_RING
---------------------------
@@ -6502,3 +6636,29 @@ KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling
KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual
machine will switch to ring-buffer dirty page tracking and further
KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail.
+
+8.30 KVM_CAP_XEN_HVM
+--------------------
+
+:Architectures: x86
+
+This capability indicates the features that Xen supports for hosting Xen
+PVHVM guests. Valid flags are::
+
+ #define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0)
+ #define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
+ #define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
+
+The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
+ioctl is available, for the guest to set its hypercall page.
+
+If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be
+provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page
+contents, to request that KVM generate hypercall page content automatically
+and also enable interception of guest hypercalls with KVM_EXIT_XEN.
+
+The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the
+KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and
+KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors
+for event channel upcalls when the evtchn_upcall_pending field of a vcpu's
+vcpu_info is set.
--
2.29.2
